Experimental Study Of Thermoelectric Generator Based On The Automotive Flue Gas

Energy shortage and environmental pollution have become problems that must be settled by all countries in the world.The rapid development of the automobile industry has accelerated energy consumption and environmental pollution,much of the energy of fuel oil wasted by car exhaust.Thermoelectric conversion technology of semiconductor has become possible to use it to recover the waste heat of automobile exhaust,having significant industrial application value.In order to improve the output power of a thermoelectric generator of waste heat recovery of automotive exhaust,a test platform was built to simulate the thermoelectric generator of waste heat recovery of automotive exhaust.Firstly,the research on the thermoelectric performance of exhaust residual heat of automotive operating condition was performed.The method of estimating and correcting the conversion efficiency of a thermoelectric generator was introduced in detail,and the theoretical value and experimental value of the thermoelectric conversion efficiency compared.Secondly,the influence of optimization of water circulating cooling and optimization of cooling fan performance and the series and parallel of thermoelectric generator unit on the performance of thermoelectric generation was studied,and the thermoelectric conversionefficiency estimated and analyzed.Finally,a set of thermoelectric generators of waste heat recovery of automotive exhaust based on combustion flue gas containing smoke was designed.Its starts up characteristics and power load characteristics and dynamic power load characteristics are studied.The method of estimating and correcting the conversion efficiency of a thermoelectric generator was introduced in detail,and the theoretical value and experimental value of the thermoelectric conversion efficiency compared.Research showing:(1)Research on the thermoelectric performance of exhaust residual heat of automotive operating condition shows that the output power of thermoelectric generator increases with the increase of flue gas velocity and the increase of flue gas temperature.At the flue gas rate and temperature and the water flow velocity being 8.5 m/s and 306 ℃ and0.039 Kg/s,the maximum output power of thermoelectric generator was28.154 W,the consuming power of water pump and fan being 10.8 W and 7.4 W,and the output maximum net power being 10.0 W.The conversion efficiency of thermoelectric generator measured by experiment was 5.23%.And theoretical calculation range of thermoelectric conversion efficiency was between 4.9% and 5.7%.(2)The research on the influence of proportional power of the water circulating on thermoelectric performance.As for the research onthe optimization of water circulation cooling,with the increase of water flow velocity,the proportional of water circulation power is higher and the net output power is less.At the flue gas velocity and temperature and water flow velocity and water cycle power proportion being 8.5 m/s and277 ℃ and 0.025 Kg/s and 0.19,the output total power of thermoelectric generator was 23.3 W,the consuming power of water pump and fan being4.5 W and 7.4 W,and the output maximum net power being 11.4 W.At the flue gas velocity and temperature and water flow velocity and water cycle power proportion being 8.5 m/s and 278 ℃ and 0.039 Kg/s and0.45,the output total power of thermoelectric generator was 24.3 W,the consuming power of water pump and fan being 10.8 W and 7.4 W,and the output maximum net power being 6.1 W.Therefore,it can be seen that the power generation capacity can be enhanced with instead of the increase of water flow velocity,but the water flow rate should be controlled reasonably to improve the power generation capacity.(3)Research on the performance optimization of the radiator fan shows that the optimal value of wind speed makes the maximum output power of a thermoelectric generator.At the flue gas velocity and temperature and water flow velocity and water cycle power proportion and fan consumption power proportion being 8.5 m/s and 277 ℃ and0.025 Kg/s and 0.19 and 0.13,the output total power of thermoelectricgenerator was 23.6 W,the consuming power of water pump and fan being4.5 W and 3.1 W,and the output maximum net power being 16 W.(4)Research on the influence of series and parallel connection of thermoelectric units on thermoelectric performance.On equipment resistance,more than 40 Ω circuits,were chosen the combination way of all series of thermoelectric unit.By equipment resistance between 20 Ωand 40 Ω circuits,were chosen the combination way of in-group series and out-group parallel of thermoelectric unit.On equipment resistance,less than 20 Ω circuits,were chosen the combination way of all series of thermoelectric unit.In this way,the maximum power output of a thermoelectric generator can be achieved.(5)Research on thermoelectric generator of waste heat recovery of automotive exhaust based on combustion flue gas containing smoke.At the flue gas rate and temperature and the water flow velocity being 1.2m/s and 418 ℃ and 0.030 Kg/s,the output stable voltage and power of a thermoelectric generator were 12 V and 37.886 W.In the case of self-power supply,the net output power of a thermoelectric generator is26.75 W.The conversion efficiency of a thermoelectric generator measured by experiment was 4.14%.And theoretical calculation range of thermoelectric conversion efficiency was between 3.94% and 4.62%.